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Abstract Background Serum CD26 (sCD26) levels were previously found diminished in colorectal cancer (CRC) patients compared to healthy donors, suggesting its potential utility for early diagnosis. Therefore we aimed to estimate the utility of the sCD26 as a biomarker for CRC and advanced adenomas in a high-risk group of patients. The relationship of this molecule with polyp characteristics was also addressed. Methods sCD26 levels were measured by ELISA in 299 symptomatic and asymptomatic patients who had undergone a colonoscopy. Patients were diagnosed as having no colorectal pathology, non-inflammatory or inflammatory bowel disease, polyps (hyperplastic, non-advanced and advanced adenomas) or CRC. Results At a 460 ng/mL cut-off, the sCD26 has a sensitivity and specificity of 81.8% (95% CI, 64.5-93.0%) and 72.3% (95% CI, 65.0-77.2%) for CRC regarding no or benign colorectal pathology. Clinicopathological analysis of polyps showed a relationship between the sCD26 and the grade of dysplasia and the presence of advanced adenomas. Hence, a 58.0% (95% CI, 46.5-68.9%) sensitivity detecting CRC and advanced adenomas was obtained, with a specificity of 75.5% (95% CI, 68.5-81.0%). Conclusions Our preliminary results show that measurement of the sCD26 is a non-invasive and reasonably sensitive assay, which could be combined with others such as the faecal occult blood test for the early diagnosis and screening of CRC and advanced adenomas. Additional comparative studies in average-risk populations are necessary.

In previous studies we described a decreased alpha-L-fucosidase activity in colorectal tumors, appearing as a prognostic factor of tumoral recurrence. The aim of this work was to extend the knowledge about tissue alpha-L-fucosidase in colorectal cancer by quantifying the expression of its encoding gene FUCA1 in tumors and healthy mucosa. FUCA1 mRNA levels were measured by RT-qPCR in paired tumor and normal mucosa tissues from 31 patients. For the accuracy of the RT-qPCR results, five candidate reference genes were validated in those samples. In addition, activity and expression of alpha-L-fucosidase in selected matched tumor and healthy mucosa samples were analyzed. According to geNorm and NormFinder algorithms, RPLP0 and HPRT1 were the best reference genes in colorectal tissues. These genes were used for normalization of FUCA1 expression levels. A significant decrease of more than 60% in normalized FUCA1 expression was detected in tumors compared to normal mucosa (p = 0.002). Moreover, a gradual decrease in FUCA1 expression was observed with progression of disease from earlier to advanced stages. These findings were confirmed by Western blot analysis of alpha-L-fucosidase expression. Our results demonstrated diminished FUCA1 mRNA levels in tumors, suggesting that expression of tissue alpha-L-fucosidase could be regulated at transcriptional level in colorectal cancer. [ABSTRACT FROM AUTHOR]

Colorectal cancer is still a major health burden worldwide, and its diagnosis has not improved in recent years due to a lack of appropriate diagnostic serum markers. Aiming to find new diagnostic proteins, we applied the proteomic DIGE technology to analyze changes in the secretome before/after differentiation of the colon adenocarcinoma Caco-2 cell line, an accepted in vitro model to study colorectal tumorigenesis. When the secretomes from undifferentiated (tumor-like) and differentiated cells (resembling healthy enterocytes) were compared, we found 96 spots differentially expressed. After MS/MS analysis, 22 spots corresponding to 15 different proteins were identified. Principal component analysis demonstrated these 22 spots could serve as a discriminatory panel between the tumor-like and normal-like cells. Among the identified proteins, the translationally-controlled tumor protein (TCTP), the transforming growth factor-beta-induced protein ig-h3 (TGFßIp), and the Niemann-Pick disease type C2 protein (NPC2) are interesting candidates for future studies focused on their utility as serum biomarkers of colorectal cancer. [ABSTRACT FROM AUTHOR]

Background: Serum CD26 (sCD26) levels were previously found diminished in colorectal cancer (CRC) patients compared to healthy donors, suggesting its potential utility for early diagnosis. Therefore we aimed to estimate the utility of the sCD26 as a biomarker for CRC and advanced adenomas in a high-risk group of patients. The relationship of this molecule with polyp characteristics was also addressed. Methods: sCD26 levels were measured by ELISA in 299 symptomatic and asymptomatic patients who had undergone a colonoscopy. Patients were diagnosed as having no colorectal pathology, non-inflammatory or inflammatory bowel disease, polyps (hyperplastic, non-advanced and advanced adenomas) or CRC. Results: At a 460 ng/mL cut-off, the sCD26 has a sensitivity and specificity of 81.8% (95% CI, 64.5-93.0%) and 72.3% (95% CI, 65.0-77.2%) for CRC regarding no or benign colorectal pathology. Clinicopathological analysis of polyps showed a relationship between the sCD26 and the grade of dysplasia and the presence of advanced adenomas. Hence, a 58.0% (95% CI, 46.5-68.9%) sensitivity detecting CRC and advanced adenomas was obtained, with a specificity of 75.5% (95% CI, 68.5-81.0%). Conclusions: Our preliminary results show that measurement of the sCD26 is a non-invasive and reasonably sensitive assay, which could be combined with others such as the faecal occult blood test for the early diagnosis and screening of CRC and advanced adenomas. Additional comparative studies in average-risk populations are necessary. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to examine the prognostic value of the preoperative serum α-L-fucosidase (AFU) activity in colorectal cancer and to assess whether it could add prognostic information that Dukes’ stages do not give. Methods: A postoperative follow-up of 137 colorectal cancer patients was performed, and survival analyses were carried out to evaluate the impact of AFU activity on disease-free survival. Dukes’ stage classification, preoperative serum carcinoembryonic antigen levels and six other clinicopathological features of the patients were also analysed. Results: In previous studies, we have stressed the diagnostic value of AFU activity in preoperatively obtained serum from colorectal cancer patients. In the present work, we have found that the enzymatic activity of serum AFU was not related to the Dukes’ stage of the primary tumour, but it was associated with the type of metastasis and recurrence of the disease. The mean value of preoperative serum AFU activity was higher in patients with distant metastases than in those with lymph node or peritoneal metastases, or without metastasis (p = 0.034). After a mean postoperative follow-up period of 22 months, three groups of patients with different recurrence rates could be distinguished (p = 0.0014). Similar results were found when only patients in Dukes’ stage B (p = 0.0439) or C (p = 0.0122) were considered. Conclusions: According to our findings, serum AFU activity appears to be a good prognostic factor of tumour recurrence in colorectal carcinoma. Furthermore, patients in Dukes’ stage B or C at high or very high risk of tumour recurrence could be spotted.Copyright © 2003 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Colorectal cancer (CRC) is the second most common cause of cancer-related deaths in Europe and other Western countries, mainly due to the lack of well-validated clinically useful biomarkers with enough sensitivity and specificity to detect this disease at early stages. Although it is well known that the pathogenesis of CRC is a progressive accumulation of mutations in multiple genes, much less is known at the proteome level. Therefore, in the last years many proteomic studies have been conducted to find new candidate protein biomarkers for diagnosis, prognosis and as therapeutic targets for this malignancy, as well as to elucidate the molecular mechanisms of colorectal carcinogenesis. An important advantage of the proteomic approaches is the capacity to look for multiple differentially expressed proteins in a single study. This review provides an overview of the recent reports describing the different proteomic tools used for the discovery of new protein markers for CRC such as two-dimensional electrophoresis methods, quantitative mass spectrometry-based techniques or protein microarrays. Additionally, we will also focus on the diverse biological samples used for CRC biomarker discovery such as tissue, serum and faeces, besides cell lines and murine models, discussing their advantages and disadvantages, and summarize the most frequently identified candidate CRC markers.

The number of potential molecular markers is constantly increasing. However, for most malignancies there is no simple test to detect early-stage tumours that is useful for screening purposes because most biomarkers have poor sensitivity or specificity, or other clinical value. One approach to increase their value is to measure several biomarkers at a time. The additional information should always yield a test more able to distinguish between patients and healthy individuals, and ideally between different kinds of tumour. Our work in colorectal, lung, and head and neck cancer, illustrates the evolution of this idea. A test in which ELISAs for key serum markers are arrayed based on immunoblot technology or flow cytometric beads is suggested because these techniques are more transferable to practical application in clinical decision making. Moreover, the multivariate data obtained from such a test can easily be managed with statistical methods already developed in the fields of genomics and proteomics.

A method to improve the reactivity to specific lectins of N-glycoproteins isolated from human colorectal mucosa and from adenocarcinoma biopsies was developed using a combination of techniques. Total protein extracts were subjected to affinity chromatography, using the immobilised lectin Concanavalin A coupled to Sepharose, by fast performance liquid chromatography (FPLC). N-glycoprotein enriched fractions were resolved by SDS-PAGE, transferred to PVDF membranes and incubated with various lectins. Digoxigenin-conjugated SNA I and MAA lectins were used to detect sialic acid residues. Biotin-conjugated UEA I lectin was used to detect L-fucose residues. By this method, lectin-binding N-glycoproteins were found in a broad relative molecular mass (Mr) range (from 47 to 205 kDa). No tissue-specific N-glycoproteins were observed when human colorectal mucosa and adenocarcinoma samples were compared.